/Engine/Source/Developer/SourceControl/Public/ISourceControlState.h
Get an item from the history
a history item or NULL if none exist
[TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< class [ISourceControlRevision](API\Developer\SourceControl\ISourceControlRevision), ESPMode::ThreadSafe > GetHistoryItem ( int32 HistoryIndex ) const